The parents of missing University of Virginia student Hannah Graham, appealed to the public to continue coming forward with information about their daughter in her last hours before she disappeared, no matter how “insignificant” it might seem.

“We need to find out what happened to Hannah, and make sure it doesn’t happen to anyone else,” said  John Graham, the father of the missing 18-year-old student.

The Grahams spoke at a press conference after police identified the man last seen with their daughter.  Surveillance videos and eyewitness accounts establish that the missing girl was with Jesse Leroy Matthew Jr., a patient technician in the university’s medical center, on the evening of her disappearance.

All surveillance videos of missing UVa. student Hannah Elizabeth Graham http://t.co/GJgaYv9rng pic.twitter.com/wBmLOxqKzW

— CBS 6 WTVR Richmond (@CBS6) September 18, 2014

Police have said that Graham, a sophomore from northern Virginia, met friends at a restaurant for dinner on the night of September 12. She then stopped by two parties at off-campus housing units and left the second party alone.

“Investigators believe that Jesse was the last person to see Hannah before she disappeared,” Charlottesville police Chief Timothy Longo said. “And look, Jesse, if you weren’t, then come forward and tell us that. If you parted ways with her, tell us that.”

WANTED for abduction of missing UVA student Hannah Graham. Known to visit DC area. Call police immediately if seen. pic.twitter.com/DuOOA2ULQE

— AU Public Safety (@AUPublicSafety) September 24, 2014

Matthew voluntarily stopped by the department’s station on Saturday with several family members, but left before investigators could ask him for information about his encounter with Graham. Police said Matthew asked for a lawyer, which was granted. After a short discussion with the lawyer, he left the station in high speed.

Although he has not been charged with the girl’s disappearance, police searched Matthew’s apartment on Monday and according to the Charlottesville Daily Progress report, left the apartment carrying several items.

However, Longo explained the police are not discounting other leads at this point. “I don’t want to get tunnel vision just because we have a name, just because we saw her with a particular person.”

UVA President Teresa A. Sullivan released a statement Sunday reiterating the university’s commitment to “provide both emotional support and physical assistance” in the search. She said the university shares the community’s goal to locate Hannah and to return her safely to her family.

College student Hannah Graham reported missing. Anyone w/ information, call 434-970-3280 http://t.co/92QEgcpu5d pic.twitter.com/sB7iHjoSjg

— The Cavalier Daily (@cavalierdaily) September 15, 2014